From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
"Andrii Nakryiko" <andriin@fb.com>, "Yonghong Song" <yhs@fb.com>,
"Song Liu" <songliubraving@fb.com>,
"Martin KaFai Lau" <kafai@fb.com>,
"Jakub Kicinski" <kuba@kernel.org>,
"David Miller" <davem@redhat.com>,
"Björn Töpel" <bjorn.topel@intel.com>,
"John Fastabend" <john.fastabend@gmail.com>,
"Jesper Dangaard Brouer" <hawk@kernel.org>,
"Arnaldo Carvalho de Melo" <acme@redhat.com>
Subject: [PATCH 06/18] bpf: Add bpf_ksym_tree tree
Date: Sun, 16 Feb 2020 20:29:53 +0100 [thread overview]
Message-ID: <20200216193005.144157-7-jolsa@kernel.org> (raw)
In-Reply-To: <20200216193005.144157-1-jolsa@kernel.org>
The bpf_tree is used both for kallsyms iterations and searching
for exception tables of bpf programs, which is needed only for
bpf programs.
Adding bpf_ksym_tree that will hold symbols for all bpf_prog
bpf_trampoline and bpf_dispatcher objects and keeping bpf_tree
only for bpf_prog objects to keep it fast.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
include/linux/bpf.h | 1 +
kernel/bpf/core.c | 60 ++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 55 insertions(+), 6 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f1174d24c185..5d6649cdc3df 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -468,6 +468,7 @@ struct bpf_ksym {
unsigned long end;
char name[KSYM_NAME_LEN];
struct list_head lnode;
+ struct latch_tree_node tnode;
};
enum bpf_tramp_prog_type {
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 604093d2153a..9fb08b4d01f7 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -606,8 +606,46 @@ static const struct latch_tree_ops bpf_tree_ops = {
.comp = bpf_tree_comp,
};
+static unsigned long
+bpf_get_ksym_start(struct latch_tree_node *n)
+{
+ const struct bpf_ksym *ksym;
+
+ ksym = container_of(n, struct bpf_ksym, tnode);
+ return ksym->start;
+}
+
+static bool
+bpf_ksym_tree_less(struct latch_tree_node *a,
+ struct latch_tree_node *b)
+{
+ return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
+}
+
+static int
+bpf_ksym_tree_comp(void *key, struct latch_tree_node *n)
+{
+ unsigned long val = (unsigned long)key;
+ const struct bpf_ksym *ksym;
+
+ ksym = container_of(n, struct bpf_ksym, tnode);
+
+ if (val < ksym->start)
+ return -1;
+ if (val >= ksym->end)
+ return 1;
+
+ return 0;
+}
+
+static const struct latch_tree_ops bpf_ksym_tree_ops = {
+ .less = bpf_ksym_tree_less,
+ .comp = bpf_ksym_tree_comp,
+};
+
static DEFINE_SPINLOCK(bpf_lock);
static LIST_HEAD(bpf_kallsyms);
+static struct latch_tree_root bpf_ksym_tree __cacheline_aligned;
static struct latch_tree_root bpf_tree __cacheline_aligned;
static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
@@ -615,6 +653,7 @@ static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
WARN_ON_ONCE(!list_empty(&aux->ksym.lnode));
list_add_tail_rcu(&aux->ksym.lnode, &bpf_kallsyms);
latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
+ latch_tree_insert(&aux->ksym.tnode, &bpf_ksym_tree, &bpf_ksym_tree_ops);
}
static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
@@ -623,6 +662,7 @@ static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
return;
latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
+ latch_tree_erase(&aux->ksym.tnode, &bpf_ksym_tree, &bpf_ksym_tree_ops);
list_del_rcu(&aux->ksym.lnode);
}
@@ -671,19 +711,27 @@ static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
NULL;
}
+static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
+{
+ struct latch_tree_node *n;
+
+ n = latch_tree_find((void *)addr, &bpf_ksym_tree, &bpf_ksym_tree_ops);
+ return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
+}
+
const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
unsigned long *off, char *sym)
{
- struct bpf_prog *prog;
+ struct bpf_ksym *ksym;
char *ret = NULL;
rcu_read_lock();
- prog = bpf_prog_kallsyms_find(addr);
- if (prog) {
- unsigned long symbol_start = prog->aux->ksym.start;
- unsigned long symbol_end = prog->aux->ksym.end;
+ ksym = bpf_ksym_find(addr);
+ if (ksym) {
+ unsigned long symbol_start = ksym->start;
+ unsigned long symbol_end = ksym->end;
- strncpy(sym, prog->aux->ksym.name, KSYM_NAME_LEN);
+ strncpy(sym, ksym->name, KSYM_NAME_LEN);
ret = sym;
if (size)
--
2.24.1
next prev parent reply other threads:[~2020-02-16 19:30 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-16 19:29 [PATCHv2 00/18] bpf: Add trampoline and dispatcher to /proc/kallsyms Jiri Olsa
2020-02-16 19:29 ` [PATCH 01/18] x86/mm: Rename is_kernel_text to __is_kernel_text Jiri Olsa
2020-02-16 19:29 ` [PATCH 02/18] bpf: Add bpf_trampoline_ name prefix for DECLARE_BPF_DISPATCHER Jiri Olsa
2020-02-16 19:29 ` [PATCH 03/18] bpf: Add struct bpf_ksym Jiri Olsa
2020-02-18 23:03 ` Daniel Borkmann
2020-02-19 9:17 ` Jiri Olsa
2020-02-16 19:29 ` [PATCH 04/18] bpf: Add name to " Jiri Olsa
2020-02-16 19:29 ` [PATCH 05/18] bpf: Add lnode list node " Jiri Olsa
2020-02-16 19:29 ` Jiri Olsa [this message]
2020-02-18 22:34 ` [PATCH 06/18] bpf: Add bpf_ksym_tree tree Daniel Borkmann
2020-02-19 8:41 ` Jiri Olsa
2020-02-16 19:29 ` [PATCH 07/18] bpf: Move bpf_tree add/del from bpf_prog_ksym_node_add/del Jiri Olsa
2020-02-16 19:29 ` [PATCH 08/18] bpf: Separate kallsyms add/del functions Jiri Olsa
2020-02-16 19:29 ` [PATCH 09/18] bpf: Add bpf_ksym_add/del functions Jiri Olsa
2020-02-16 19:29 ` [PATCH 10/18] bpf: Re-initialize lnode in bpf_ksym_del Jiri Olsa
2020-02-16 19:29 ` [PATCH 11/18] bpf: Rename bpf_tree to bpf_progs_tree Jiri Olsa
2020-02-16 19:29 ` [PATCH 12/18] bpf: Add trampolines to kallsyms Jiri Olsa
2020-02-16 19:30 ` [PATCH 13/18] bpf: Return error value in bpf_dispatcher_update Jiri Olsa
2020-02-16 19:30 ` [PATCH 14/18] bpf: Add dispatchers to kallsyms Jiri Olsa
2020-02-16 19:30 ` [PATCH 15/18] bpf: Sort bpf kallsyms symbols Jiri Olsa
2020-02-18 23:18 ` Alexei Starovoitov
2020-02-19 8:30 ` Jiri Olsa
2020-02-16 19:30 ` [PATCH 16/18] perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event Jiri Olsa
2020-02-16 19:30 ` [PATCH 17/18] perf tools: Set ksymbol dso as loaded on arrival Jiri Olsa
2020-02-16 19:30 ` [PATCH 18/18] perf annotate: Add base support for bpf_image Jiri Olsa
2020-02-26 13:03 [PATCHv3 00/18] bpf: Add trampoline and dispatcher to /proc/kallsyms Jiri Olsa
2020-02-26 13:03 ` [PATCH 06/18] bpf: Add bpf_ksym_tree tree Jiri Olsa
2020-02-26 23:10 ` Song Liu
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